Preparation and properties of carbides (Ti, W, Cr)C

Summary

1.

(Ti, W, Cr) C solid solutions may be obtained by carbidization of TiO2+ WC+ Cr2C3+ C charges in hydrogen. With increasing chromiun content the carbidization temperature should fall and at 25 wt.% Cr3C2 will be less than 1923 °K (the duration of heating depends on the amount of change in the container).

2.

By using intensified grinding the authors obtained fine-grained carbide powders, from which compact specimens with virtually theoretical densities were obtained by pressing, followed by sintering in vacuum at 2073–2123 °K.

3.

With increasing Cr3C2 content the scaling resistance and electrical resistance of (Ti, W, Cr) C solid solutions increase markedly, and the modulus of elasticity falls. At room and elevated temperatures the hardness is virtually unchanged. The coefficient of thermal expansion, the bending strength and the contact angle of wetting by cobalt (in vacuum) are also virtually constant with changing composition of the solid solution in the concentration range studied. The contact angle of wetting of a (Ti, W) C solid solution by cobalt at the melting point of the metal in vacuum was zero. Similar results were obtained for specimens with 10 and 20% Cr3C2. Additions of chromium carbide therefore do not impair the wettability of (Ti, W) C solid solutions by cobalt.